Quick Links

Sudbury retune.

A week or two ago I started getting pop-up messages on some of the the Freeview channels stating that a retune would be required on 1st August. Sure enough on the day some channels had disappeared so I did the retune. All the com4 channels promptly disappeared and have not returned despite several further retunes. Ive done a bit of research and it seems this may be part of the "700MHz clearance event" - whatever that means. We get channels from Sudbury - anyone got any idea of what has happened or how I might get Com4 back?

Comments

It sounds like you may have a Group B aerial which is now struggling to get a signal from the mux on it's new frequency. If that is the case then a change of aerial will be required.

700Mhz clearance refers to the Government flogging off yet another chunk of what used to be TV broadcast spectrum to the mobile phone operators. Meaning the existing TV services are being squeezed into ever less room on the UHF bands. Hence all this retuning as services in the band being sold off have to be moved. Sometimes resulting in the need to change aerial as the new frequencies are out of band for the existing aerial.

The SDN or COM4 mux has changed to UHF Channel 29, I stayed at a hotel in Clacton back in April and found that the aerial they had could not pick up Arqiva B on Channel 37, all the hotels rooms were sharing the one aerial so my guess was it was not using a powered distribution system,

Viewers may be eligible for free in-home support, including aerial work if needed.

Anyone who needs advice, or who finds they are still missing services after re-tuning, can visit the Freeview website at www.freeview.co.uk/tvchanges or contact the Freeview advice line free on 0808 100 0288.

Thanks for the replies. Up until now we have always received all available channels (no Com7 or Com8 from Sudbury) with excellent picture quality. That suggests to me that we already have a decent aerial which is correctly aligned to the Sudbury transmitter. Why should the existing aerial now not be good enough if we are still receiving signals from the same transmitter? Would it be worth trying some sort of signal booster?

I apologise if these are stupid questions but my tech knowledge is not that great! If we need a new aerial then so be it - but I'm keen to explore all other possibilities first.

Thanks for the replies. Up until now we have always received all available channels (no Com7 or Com8 from Sudbury) with excellent picture quality. That suggests to me that we already have a decent aerial which is correctly aligned to the Sudbury transmitter. Why should the existing aerial now not be good enough if we are still receiving signals from the same transmitter? Would it be worth trying some sort of signal booster?

I apologise if these are stupid questions but my tech knowledge is not that great! If we need a new aerial then so be it - but I'm keen to explore all other possibilities first.

The frequencies used by the Sudbury transmitter have changed. That is the important point. TV aerials can be either wide band, ie they cover all available frequencies used for TV broadcasting, or they can be Grouped, ie they cover a narrower range of frequencies. In the early days Grouped aerials were pretty much the norm as the various TV channels from any particular transmitter were grouped together in a narrow sub-set of the entire UHF band. Plus it is often easier to design an aerial to cover a smaller range of frequencies.

This was OK as long as any new services were also within the sub-band covered by the aerial. However part of the UHF band is being sold off to the mobile phone operators. Which means any services currently using those frequencies have to be moved into what is left of the band for TV broadcasts.

In some cases this has resulted in some services being shifted onto frequencies outside of the range covered by a Grouped aerial which previously worked OK for that transmitter. So even though the aerial and all the cabling etc may be in perfect working order you can't get certain services simply because they are now on a frequency the aerial was never designed to cover. This is what has happened at Sudbury and is possibly what has happened with your reception.

If it is the case that the frequency now used by a particular service is outside the range of your aerial, there is nothing you can do about that other than change the aerial for a type that does cover the range of frequencies now being used. A signal booster won't help. It can magic a signal out of the ether that simply isn't there on the feed from the aerial. Or if there is a signal present but it is so weak that it is badly affected by noise it still won't help. All it will do is amplify the noise along with the signal meaning the TV still won't be able to make any sense of what it is being fed.

In the past uk aerials were "grouped" this meant that an aerial was designed to be more sensitive to some frequencies rather than others ....
Sudbury used to have its frequencies on these UHF channels
BBC-A (PSB1) 44
D3&4 (PSB2) 41
BBC-B^ (PSB3) 47
SDN (COM4) 58
Arqiva A (COM5) 60-
Arqiva B (COM6) 56

This worked quite well with a group B aerial which is nominally uhf channel 35 to 53

Because the government is selling off more frequencies above 700 MHz to mobile phones
which is ch 48
The comm muxes at Sudbury have been moved to 29 31 37 ...

So I suggest you phone the freeview help line ..
If you rely on Freeview it is likely that they will replace you aerial free of charge
This uses money from the mobile phone companies via the government .

In the past uk aerials were "grouped" this meant that an aerial was designed to be more sensitive to some frequencies rather than others ....
Sudbury used to have its frequencies on these UHF channels
BBC-A (PSB1) 44
D3&4 (PSB2) 41
BBC-B^ (PSB3) 47
SDN (COM4) 58
Arqiva A (COM5) 60-
Arqiva B (COM6) 56

This worked quite well with a group B aerial which is nominally uhf channel 35 to 53

Because the government is selling off more frequencies above 700 MHz to mobile phones
which is ch 48
The comm muxes at Sudbury have been moved to 29 31 37 ...

The B group is indicated by the yellow line on that diagram. What the yellow line has is 29 / 31 /37 all having having a HIGHER gain than any of 56 / 58 / 60.
This also reflects my reception with a group B aerial. Before the recent change that group B aerial could not receive COM4/5/6 from Sudbury but now they are coming in strong enough not to have any breakup 24 hours.

Bounder is unlikely to have a group B aerial based on it past performance and what your link actually states as the likely typical frequency range and strengths for an aerial of group B.

... I suggest you phone the freeview help line ..
If you rely on Freeview it is likely that they will replace you aerial free of charge
This uses money from the mobile phone companies via the government .

Agree with that as the exact technical details to account for the loss does not have to be fully understood for a replacement to be funded.

After reading the helpful replies (thanks again!) and doing a bit of reading around I was convinced we needed a new aerial. I also tried manual tuning on Ch 29 and noticed that the signal quality was 0%! I did this several times over the following days and once or twice the signal quality was around 5% but usually zero. So I gave up and decided to sort out a new aerial after our holidays in a few weeks time.

A few days later something unexpected happened. We were watching the TV and when the adverts came on I switched to the manual tuning menu and the signal quality on Ch 29 was fluctuating between 40 - 50%. I immediately ran a scan and all the com4 channels reappeared in their correct positions on the EPG. For the rest of that evening and the following two days we were able to watch all the com4 channels. The picture quality was generally good, there was occasionally a brief flicker of pixellation but it was perfectly watchable. Then yesterday evening Ch29 signal quality was back to 0% and we cannot get a picture on any com4 channels. It was the same this morning.

All this has left me completely confused. I believed it was an aerial issue but how can that explain the huge variation in signal quality - from 0% to 58% (which is the highest I remember). Anybody got any ideas?

Not sure if it makes any difference but our set-up is that the aerial cable runs from the aerial point in the wall to a BT Youview box. A second cable connects the box to a Samsung smart TV. About 95% of our viewing is direct from the TV and we only use the youview box to watch BT sport or to make/watch recordings.

After reading the helpful replies (thanks again!) and doing a bit of reading around I was convinced we needed a new aerial. I also tried manual tuning on Ch 29 and noticed that the signal quality was 0%! I did this several times over the following days and once or twice the signal quality was around 5% but usually zero. So I gave up and decided to sort out a new aerial after our holidays in a few weeks time.

A few days later something unexpected happened. We were watching the TV and when the adverts came on I switched to the manual tuning menu and the signal quality on Ch 29 was fluctuating between 40 - 50%. I immediately ran a scan and all the com4 channels reappeared in their correct positions on the EPG. For the rest of that evening and the following two days we were able to watch all the com4 channels. The picture quality was generally good, there was occasionally a brief flicker of pixellation but it was perfectly watchable. Then yesterday evening Ch29 signal quality was back to 0% and we cannot get a picture on any com4 channels. It was the same this morning.

All this has left me completely confused. I believed it was an aerial issue but how can that explain the huge variation in signal quality - from 0% to 58% (which is the highest I remember). Anybody got any ideas?

Atmospheric conditions. Reception can fluctuate with changes in atmospheric conditions, a common effect is being able to receive distant transmitters which normal can't be. So always possible a change in conditions affected the signal strength for a few days meaning there was just enough signal received to allow you to watch those channels. But long term you may find a new aerial is far more reliable than the British Weather

The SDN or COM4 mux has changed to UHF Channel 29, I stayed at a hotel in Clacton back in April and found that the aerial they had could not pick up Arqiva B on Channel 37, all the hotels rooms were sharing the one aerial so my guess was it was not using a powered distribution system,

I do not get anything on channel 29 here to in Clacton though do seem to have all the channels such as Sky News , Pick TV , Realy , Paramount & Sony movies So think its coming from Dover or bluebell hill on the back of the aerial I am lucky. on roof aerial
Not sure the clacton transmitter is even doing anything as the signal is very weak on an indoor one on the old numbers channels 52 and 48 were always 100% now they are about 30% less

The SDN or COM4 mux has changed to UHF Channel 29, I stayed at a hotel in Clacton back in April and found that the aerial they had could not pick up Arqiva B on Channel 37, all the hotels rooms were sharing the one aerial so my guess was it was not using a powered distribution system,

I do not get anything on channel 29 here to in Clacton though do seem to have all the channels such as Sky News , Pick TV , Realy , Paramount & Sony movies So think its coming from Dover or bluebell hill on the back of the aerial I am lucky. on roof aerial
Not sure the clacton transmitter is even doing anything as the signal is very weak on an indoor one on the old numbers channels 52 and 48 were always 100% now they are about 30% less

If you get your reception from the Sudbury transmitter the channels that you have listed (Sky News, Pick etc) are on channel 31. The channels we have lost on channel 29 are Drama, Five USA, Horror and a number of others. Are you able to receive those channels?

according to MB21 the Clacton Relay is going to include the the remaining muxes, so all 6 will be available, Wivenhoe Park has also switched to 6 muxes. sorry for the late reply but the hotel was using Sudbury

An update on this for anyone interested. We had a new aerial installed several weeks ago and all the Com4 channels reappeared. Happy days. All was well until one day two or three weeks ago when I noticed we couldn't get a picture on any of the Com5 or Com6 channels. Signal strength and quality were both at 0%. The following morning all channels were back with signal quality at 100% and strength 90 - 100%.

Since then it has followed a similar pattern almost every day. In the morning we have all the channels with signal strength of 90 - 100% but it then collapses down to 0% on Coms 5 + 6. By late morning we cannot receive any of these channels but they do return every evening - time varies between 9pm and midnight. The only explanation I can think of is that there is something going on at the transmitter and the digital uk website has been showing engineering works at Sudbury. However this week it looks as though the works have finished but our reception problems persist. So I have contacted the man who installed the aerial and he is coming to investigate later this week. Chrisjr will be pleased to hear that I have not done any retunes!

Our old Sudbury back aerial seems to work really well lately UHF 29 mux is hardest to pick up but works OK in the other room.
in my room the aerial uses Clacton TX.
but many other people are not able to get Sudbury that well many had aerials put up just 3 years ago and his signal is really bad and the channels all breakup a lot.

An update on this for anyone interested. We had a new aerial installed several weeks ago and all the Com4 channels reappeared. Happy days. All was well until one day two or three weeks ago when I noticed we couldn't get a picture on any of the Com5 or Com6 channels. Signal strength and quality were both at 0%. The following morning all channels were back with signal quality at 100% and strength 90 - 100%.

Since then it has followed a similar pattern almost every day. In the morning we have all the channels with signal strength of 90 - 100% but it then collapses down to 0% on Coms 5 + 6. By late morning we cannot receive any of these channels but they do return every evening - time varies between 9pm and midnight. The only explanation I can think of is that there is something going on at the transmitter and the digital uk website has been showing engineering works at Sudbury. However this week it looks as though the works have finished but our reception problems persist. So I have contacted the man who installed the aerial and he is coming to investigate later this week. Chrisjr will be pleased to hear that I have not done any retunes!

Anyone got any theories as to what might be happening?

I would be surprised if it was engineering work going on, unless it was unplanned emergency work. Arqiva have to get approval from the affected broadcasters to do any planned work. It would be exceptional if any agreed to the transmitter being off or on seriously reduced power during peak time in the evening. Most planned work either takes place during daytime if work on the mast is involved or in the early hours if working on the transmitters.

So planned work could account for the daytime problems, even more so if you are in a fringe reception area where any reduction in signal would be most noticed. But I would be surprised if it accounts for the evening problem. One possibility is some odd local source of interference that is blatting out the part of the spectrum COM5/6 use. A competent installer with a decent spectrum analyser hooked up to the aerial should be able to spot that.

Following the clearance retune on Sudbury in the summer I lost all but the main three multiplexes, and this was quite a common occurrence locally among people who (like me) had new wideband aerials fitted recently. All six multiplexes should be on the same power as before, but I suspect that some multiplexes are no longer on an omni-directional pattern and perhaps that is why Clacton is getting the rest of the multiplexes. If this is the case it would have been nice to have been told, but the signal strength of the missing three from Sudbury is incredibly weak in comparison so there must be some difference.

The general remedy was to change over to satellite, but if Clacton is getting an upgrade an aerial repoint might be the long term fix.

Following the clearance retune on Sudbury in the summer I lost all but the main three multiplexes, and this was quite a common occurrence locally among people who (like me) had new wideband aerials fitted recently. All six multiplexes should be on the same power as before, but I suspect that some multiplexes are no longer on an omni-directional pattern and perhaps that is why Clacton is getting the rest of the multiplexes. If this is the case it would have been nice to have been told, but the signal strength of the missing three from Sudbury is incredibly weak in comparison so there must be some difference.

The general remedy was to change over to satellite, but if Clacton is getting an upgrade an aerial repoint might be the long term fix.

Suzie x

I don't think anything further is planned for Clacton. It had the three COM Muxes added on Aug 1st 2018 (the same day Sudbury had its clearance retune)

It might be a better bet for you (and/or possibly also Wivenhoe Park, that also now carries the COMs)

Took down the old Televes 48 element Sudbury aerial. Was bought about twenty years ago when I got the first digital TV but subsequently about half the directors have fallen off along with half the reflector (we have very fat pigeons). In those days a second much larger aerial (Televes DAT75 with MRD pre-amp giving 30dB gain total) was required to get ITV from Dover on channel 68 and that was still in good condition so repointed that to Sudbury and now good 100% signal strength on all but channel 37 which is only showing 98%. Quality is 100% on all.

I did try Clacton but my assistant managed to unplug the aerial from the receiver while dusting so no signal was received while I was on the roof. ERP and relative distance suggests that Clacton would be weaker than Sudbury on the main multiplexes anyway. I do live outside official terrestrial coverage anyway so I guess any coverage is good.

I am sure that signal strength is weaker on the Sudbury channel 37 multiplex and possibly the others as well judging by the experience of people locally with previously adequate and new wideband aerials. At least now unlike before switchover the weak signals are not being swamped by +40dB of analogue!

I have connected the downlead that was used for the old aerial to the satellite dish so can now get satellite on the telly. Nice to have our local ITV region in HD rather than the Maidstone based one that is broadcast from Sudbury (the same as Dover coincidently). I thought that Virgin Media were a bit shoddy when they thought that local ITV for Essex comes from Cambridge rather than Norwich, but that was slightly better that whatever FreeviewHD have managed.

Thank you for the assistance. I think that the real answer for me is that all new televisions will have to have satellite tuners in them.